Multibarrel injectors of fuel pellets for injection into plasmas of the HL-1M, HT-6M, and T-10 tokamaks

Pellet injectors developed at PELIN for JET, TAE and HL-2A

“…Deuterium gas is supplied into all barrels simultaneously and is frozen in the cells forming pellets. The technology for fabrication good quality pellets is described in [9]. A helium propellant gas provides reliable injection at velocities over 500 m/s because a pressure over 1 MPa is necessary to break away the frozen pellet from barrel walls.…”

A 12-barrel deuterium pellet injector for the C-2 field-reversed configuration device

“…The injector was designed on the basis of the prin ciples that are presented in [4] and formulated using the analysis of previously developed and successfully operated multibarrel injectors. Figures 1 and 2 show, respectively, the injector diagram and its appearance.…”

“…The operating principle of this injector is similar to that described in [4]. At a certain pressure, deuterium arrives from the gas supply system, is fed into all bar rels, and is frozen in the cells, thus forming pellets.…”

“…Otherwise, they will fly through plasma having no time to evaporate. Among more than 100 fuel injectors of all types that have been developed by now, the simplest and most reliable devices are those in which pellets are formed directly in barrels via gas freezing at T = 6-10 K [4][5][6][7][8]. However, in this case, pellets freeze to the barrel walls and in order to displace them, a considerable pressure (>1 MPa) of the accelerating gas is required, especially when the length to diameter ratio appreciably exceeds unity.…”